Relay switching circuit utilizing an enabling voltage source



G. N. HALPIN Oct. 1l 1966 RELAY SWITCHING CIRCUIT UTILIZING AN ENABLING VOLTAGE SOURCE Filed Feb. 26, 1963 V M Y mww N. i

www B United States Patent O M 3,278,810 RELAY SWITCI-IING CIRCUIT UTILIZING AN ENABLING VOLTAGE SOURCE George N. Halpin, Phoenix, Ariz., assiguor to General Electric Company, a corporation of New York Filed Feb. 26, 1963, Ser. No. 261,057 4 Claims. (Cl. 317-157) This inventi-on relates to relay circuits. More partic- .ularly, it relates to a circuit for eifecting operation of a multiplicity of relay operated output circuits without the need of an intermediate enabling relay.

In many situations such as in process control wherein a control computer is utilized, the output signals from such computer actuate external equipment such as c-ontrol circuits, annunciators, regulators, etc. Since the computer itself is a high speed device, it is most eiciently utilized when-the external equipment is also capable of high speed operation. In this connection, relays such as the mercury wetted-magnetic latched type are comparatively high speed elements, their -operating time being in the order of about two milliseconds.

Heretofore, where such relays have been utilized, there has been required an intervening enabling relay except possibly in those situations wherein only a single contact action is desired. Of necessity, the time required for the actua-tion of the enabling relay tends to prevent high speed operation of the external equipment.

Accordingly, it is an important object of this invention to provide an arrangement for effecting the operation of a` large number of relay output circui-ts without the need for the? time consuming operation of an enabling relay. It is another object to provide an arrangement in accordance with the preceding object wherein the relay circuits are operated from the logical circuitry of computer equipment.

'Generally speaking and in accordance with the invention, Ithere are provided in combination, a given plurality of relays, each of the relays being capable of being in one of two discrete states, each of the relays having first and second terminals and 'having a chosen operating voltage. A first reference voltage source is coupled to 'the first terminals of -the relays. A second and enabling voltage source is adapted to be coupled to both the iirst and second terminals of each relay and a plurality of third voltage sources for producing voltages having opposite polarities are adapted to be coupled to the second terminals of each relay. Thevalues of the voltages are chosen such that the coincidence of second and third voltages at the respective terminals of a relay cause current to flow through the relay to place it in one of two states as determined by the positive or negative nature of the third voltage. The occurrence of only the third voltage causes no current to flow and the respective relay remains in its previous state. The occurrence of only the second voltage causes current to flow in the same direction as that caused by the coincidence of the second voltage and a third voltage of negative polarity and causes the relays to assume the corresponding state.

The novel features, which are believed to be characteristic of this invention, are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation together with other and further objects thereof may best be understood when taken in connection with the accompanying drawing.

The drawingis a schematic depiction of an arrangement constructed in accordance with the principles of the invention.

Referring now to the drawing, relays 10, 20 and 30 are preferably high speed operating relays capable of being in a set and a reset state. They may suitably be mercury 3,278,810I Patented oct. 11, 1966 wetted-magnetic latched relays which have an operating time of less than two milliseconds. For convenience, current flow in relay 10 from terminal 11 to terminal 9 thereof may be considered as placing it in the set state, in such state, the contact 12 associated with relay 10 being in the position as shown in the drawing and thereby connecting the voltage source 14 to the utilization circuit 16 of the external equipment. Terminal 9 is connected to a source of positive potential 18 through the anode to cathode path of a diode 17 and to ground through the cathode to anode path of a diode 21. Terminal 11 is connected to an enabling voltage source 13 through a resistor 15.

Stage 2 may be a logic circuit in a computer whose output may be one of two voltage levels, such as plus 6 and minus 6 volts, or plus 6 volts and open circuit, the output of stage 2 being applied to terminal 11 through the anode to cathode path of a diode 4.

Each of relays 20 and 30 are similarly arranged in circuit as relay 10, the outputs of stages 22 and 32 providing the source voltage levels similar to stage 2. Each of relays 10, 20 and 30 suitably may have the same operating voltage. Voltage sources 8, 18, 28 and 38 may suitably have the same value as the value of the upper voltage level output from stages 2, 22 and 32. Enabling voltage source 13 when actuated through a logic arrangement or otherwise (not shown) produces a negative voltage of a suitable value, such value being about minus 18 volts when the values of the positive voltage sources are plus 6 volts, the voltage level outputs from stages 2, 22 and 32 are plus 6 volts and minus 6 volts and the operating voltage of relays 10, 20 and 30 is plus 6 volts. The enabling voltage source is connected to junction 23 of diodes 17 and 21 through a resistor 24.

In considering the operation of the arrangement shown in the drawing, let it be assumed that with the voltage values as set forth, a plus 6 volts level is produced from stage 2 and coincidentally minus 18 volts is produced from source 13. Current will now flow through relay 10 from terminal 11 to terminal 9, to junction 23 and thence back to source 13 through resistor 24 to place relay 10 in the set state. It on the other hand, a minus 6 volts output is produced from stage 2 and a minus 18 volts output is coincidentally produced from source 13, current llows from junction 23 through relay 10` from terminal 9 to terminal 11 and thence yto lsource 13 through resistor 15 to place relay 10 in the reset state. Relay 10` is also placed in the reset state in the same manner if the only enabling rvoltage is produced from source 13 and the circuit is open between stage 2 and terminal 11. Of course, in the event that no enabling volta-ge is produced from source 13, then no circuit action occurs and the relays remain in their previous states.' It is seen in the drawing, that the output from stage 2 may be utilized to operate similar relay circuits which are not shown.

The values of resistors 15, 26 and 29 respectively are chosen `such that they conduct current with a voltage drop equal to or less than the voltage of source 13 minus the nominal operating voltage of a single relay. The value of resistor 24 is chosen such that it conducts current from `all of the relays with a voltage drop equal to or less than the voltage of source 13 minus the nominal operating voltage produced by all relays 10, 20 and 3o, for example, conducting in the same direction in parallel.

Diodes 4, 25 and 34 function to isolate the voltages from the respective stages 2, 22 and 32 from affecting each other. Diodes 6, 27, and 35 are inductance surge suppression diodes for relays 10, 20 and 3G respectively. Diode 21 prevents the ilow of current to common, i.e., ground when the enabling voltage is not present at the output of source 13.

While there has Ibeen shown a particular embodiment of the invention, it will, of course, be understood that it is not wished to be limited thereto since different modifications may be made both in the circuit arrangements and in the instrumen-talities employed, and it is contemplated in the appended claims to cover any such modifications as fall within the true spirit and scope of the invention.

What is claimed as new 'and desired to be secured by Letters Paten-t of the United States is:

1. In combination, a given plurality of relays, each of said relays being capable of being in one of two discrete states, each of said relays having first and second te-rminals and having a chosen operating voltage, a first reference voltage source to which said tirst terminals are coupled, a second voltage source comprising a terminal coupled ,to said first relay terminals by a single circuit means and coupled to said second relay terminals by individual circuit means for each respective second relay terminal, a given plurality of third sources for producing voltages having opposite polarities and adapted to be coupled to said second terminals -respec-tively, the values of said voltages being so chosen that the coincident occurrence of said second voltage and a third voltage of one of said polarities causes current to flow in one direction through -a -relay to place it in one of said states, the coincident occurrence of said sec-ond voltage and a third voltage of the other of ysaid polarities causes current to iiow in the opposite direction th-rough said relay to place it in the other of said states, the occurrence of only said second voltage causing said relay to be placed in `the other of said states, the occurrence of only said third voltage causing the state of said relay to remain unchanged.

2. In combination, a given plurality of relays, each of said relays being capable of being in one of two discrete states, each of said relays having first and second terminals and having a chosen operating voltage, a first reference voltage source comprising a terminal to which said first terminals are coupled, a given plurality of resistances, a common resistance, a second voltage source comprising one terminal coupled to each of said second terminals through a respective one of the resistances comprising said plurality and to said first source terminal through said common resistance, a given plurality of third sources for producing voltages having opposite polarities and adapted to be coupled to said second terminals respectively, the values of said last named voltages and said resistances being so chosen lthat the coincident occurrence of said second voltage and a third voltage of one of said polarities causes current to flow in one direction through a relay to place it on one of said states, the coincident occurrence of said second voltage and a third voltage of the other of said polarities causes current to flow in the opposite direction through said rel-ay to place it in the other of said states, the occurrence of only said second voltage causing current to tlow in said opposite direction through said relay to place i-t in the other of said states, the `occurrence of only said third voltage causing the state of said relay to remain unchanged.

3. In the Acombination defined in claim 2 wherein each of the resistances of said plurality :has a value such that the voltage drop thereacross does not exceed the value of said second voltage minus the chosen operatin-g voltage of a relay land the value of said common resistance is such that the voltage drop thereacross does not exceed the value of said Isecond voltage.

4. A register for binary lcoded signals comprising a row of two state switches, a row of binary signal input terminals one for each switch, at least one common input terminal, a point of substantially fixed potential, each of said switches comprising a winding the direction of current in which determines the state of the switch, first unilaterally conductive devices connected from one end of each of said windings to a respective signal input terminal, means comprising individual circuits coupled from said one end of each of said windings -t-o said common input terminal, a second unilaterally conductive device connected from the other end of each of said windings to said point of substantially fixed potential, means comprising a further circuit coupled rbetween said other end of each of said windings to said one common input terminal, means for applying binary signals to the respective binary signal input terminals, means for applying an enatbling signal to said comm-on input terminal, the polarity of said binary signals being predetermined in relation to said substantially fixed potential, said enabling signal and the polarity of said unilaterally conductive devices and said individual and further circuits being dimensioned to cause said switches to switch to one state in response to the simultaneous occurrence of an enabling signal and a respective binary signal of a first level, to cause said switches to switch to -the other state in response to the simultaneous occurrence of an enabling signal and a respect-ive binary signal a second level, t0 cause said switches to switch to one state in response to the occurrence of only said enabling signal, and to cause said switches to remain unchanged in response to the occurrence of only binary signals,

SAMUEL BERNSTEIN, STEPHEN W. CAPELLI,

Examiners.

I. A. SILVERMAN, Assistant Examiner. 

1. IN COMBINATION, A GIVEN PLURALITY OF RELAYS, EACH OF SAID RELAYS BEING CAPABLE OF BEING IN ONE OF TWO DISCRETE STATES, EACH OF SAID RELAYS HAVING FIRST AND SECOND TERMINALS AND HAVING A CHOSEN OPERATING VOLTAGE, A FIRST REFERENCE VOLTAGE SOURCE TO WHICH SAID FIRST TERMINALS ARE COUPLED, A SECOND VOLTAGE SOURCE COMPRISING A TERMINAL COUPLED TO SAID FIRST RELAY TERMINALS BY A SINGLE CIRCUIT MEANS AND COUPLED TO SAID SECOND RELAY TERMINALS BY INDIVIDUAL CIRCUIT MEANS FOR EACH RESPECTIVE SECOND RELAY TERMINAL, A GIVEN PLURALITY OF THIRD SOURCES FOR PRODUCING VOLTAGES HAVING OPPOSITE POLARITIES AND ADAPTED TO BE COUPLED TO SAID SECOND TERMINALS RESPECTIVELY, THE VALUES OF SAID VOLTAGES BEING SO CHOSEN THAT THE COINCIDENT OCCURRENCE OF SAID SECOND VOLTAGE AND A THIRD VOLTAGE OF ONE OF SAID POLARITIES CAUSES CURRENT TO FLOW IN ONE DIRECTION THROUGH A RELAY TO PLACE IT IN ONE OF SAID STATES, THE COINCIDENT OCCURRENCE OF SAID SECOND VOLTAGE AND A THIRD VOLTAGE OF THE OTHER OF SAID POLARITIES CAUSES CURRENT TO FLOW IN THE OPPOSITE DIRECTION THROUGH SAID RELAY TO PLACE IT IN THE OTHER OF SAID STATES, THE OCCURRENCE OF ONLY SAID SECOND VOLTAGE CAUSING SAID RELAY TO BE PLACED IN THE OTHER OF SAID STATES, THE OCCURRENCE OF ONLY SAID THIRD VOLTAGE CAUSING THE STATE OF SAID RELAY TO REMAIN UNCHANGED. 